As much as I don't want it to be true...I believe that it won't be long for American does something similar.
I don't know exactly what has been confirmed, but there was a lot of chatter a few months ago (April-June) about AA going dynamic.
@wasCB14 I do remember some chatter about it now that you mention it. I just tried a google search and there hasn't been anything new and I'm hoping it stays that way. But what I did get this evening was an email from American saying that they're ending their partnership with Alaska Airlines starting March 2020. No more redemption on Alaska via AAdvantage and vice versa for Mileage Plan.
What's interesting is that they're still partnering on lounge access which is still a perk for AAdvantage Executive cardholders but it does suck that I won't be able to burn AAdvantage miles on Alaska as they have a couple of non-stop routes from here to Sea-Tac and San Diego that I use a few times a year.